1. Field of the Invention
The present invention is related to a one-shot circuit, and more particularly, to a one-shot circuit capable of being integrated into a chip.
2. Description of the Prior Art
Please refer to FIG. 1. A one-shot circuit generates a delay signal SDELAY according to an input signal SIN. When the one-shot circuit receives the input signal representing “enabling”, the delay signal SDELAY generated by the one-shot circuit represents “enabling”; and when the input signal SIN changes from representing “enabling” to “not enabling”, the delay signal SDELAY generated by the one-shot circuit continues to represent “enabling” for a delay period TDELAY. In the one-shot circuit, a clock signal generator is required for generating a reference clock signal so as to control the period length of the delay period TDELAY. Generally speaking, the clock signal generator of the one-shot circuit is realized by a phase-shifting circuit (also referred to as an RC oscillator).
However, when the required period length of the delay period TDELAY is longer, resistance and capacitance of the RC oscillator of the one-shot circuit are required to be larger. In other words, when the one-shot circuit is integrated into a chip, the RC oscillator of the one-shot circuit occupies such a large area in the chip that the cost of the chip vastly increases. Therefore, in the prior art, both the capacitor and the resistor of the RC oscillator of the one-shot circuit are external to the chip. However, it is inconvenient for the user to place the additional capacitor and resistor on the printed circuit board.